Chien-Hua Tu

My research focus has been bridging the fundamentals of polymer physics with applications in different areas like the design of novel polymer materials and recycling of polymers. My previous doctoral research aimed to understand if and how polymer chains penetrate narrow pores. To that end, I developed a nanofluidic method based on dielectric spectroscopy, so called in situ nanodielectric spectroscopy (nDS), that enables the real-time simultaneous investigation of molecular dynamics, imbibition kinetics, and effective viscosity experienced by polymers during flow inside nanopores. Using this method, I investigated the nonequilibrium adsorption behavior of polymers onto pore surface via the evolution of dielectric intensity and relaxation time distribution of polymer segmental dynamics and normal mode chain dynamics recorded during and after imbibition. In addition, ion transport behaviors during infiltration of polymer electrolytes into nanopores were also studied by nDS. My current postdoctoral research is aiming to investigate the chemical upcycling of polymers. More specifically, I am proceeding with two major directions: First, I am establishing the structure-property-relationship of new polymers fabricated from the upcycling reactions (dehydrogenation and subsequent functionalization) of polyolefins. Meanwhile, I am trying to identify the contribution of changes in polymer chain conformations to polymer upcycling efficiency. Several techniques are involved such as dielectric spectroscopy and X-ray scattering.